There has been an effort in recent years, with significant success, to discover new drug compounds that act by stimulating certain key aspects of the immune system, as well as by suppressing certain other aspects (see, e.g., U.S. Pat. No. 6,039,969 (Tomai et al.) and U.S. Pat. No. 6,200,592 (Tomai et al.). These compounds, referred to herein as immune response modifiers (IRMs), appear to act through basic immune system mechanisms known as Toll-like receptors (TLRs) to induce selected cytokine biosynthesis, induction of co-stimulatory molecules, and increased antigen-presenting capacity.
Many IRMs may be useful for treating a wide variety of diseases and conditions. For example, certain IRMs may be useful for treating viral diseases (e.g., human papilloma virus, hepatitis, herpes), neoplasias (e.g., basal cell carcinoma, squamous cell carcinoma, actinic keratosis, melanoma), TH2-mediated diseases (e.g., asthma, allergic rhinitis, atopic dermatitis), and auto-immune diseases. Certain IRMs may also be useful, for example, as vaccine adjuvants.
Many known IRMs are imidazoquinoline amine derivatives (see, e.g., U.S. Pat. No. 4,689,338 (Gerster)), but other compound classes are known as well (see, e.g., U.S. Pat. No. 5,446,153 (Lindstrom et al.); U.S. Pat. No. 6,194,425 (Gerster et al.); and U.S. Pat. No. 6,110,929 (Gerster et al.); and International Publication Number WO2005/079195 (Hays et al.).
In view of the great therapeutic potential for IRMs in the treatment of a wide variety of diseases and conditions, and despite the important work that has already been done, new compounds that can effectively modulate the immune response, by induction of cytokine biosynthesis or other mechanisms, are still needed.